Method and apparatus for heating trains



Jan. 11, 1966 D, s. NEUHART METHOD AND APPARATUS FOR HEATING TRAINSFiled March 1, 1963 mozmwzmo 265 52322 wok/2556 INVENTOR mm uZTUZm JHIJwmma DAVID SAN BORN NEUHART ATTORNEYS United States Patent 3,228,606METHOD AND APPARATUS FOR HEATING TRAINS David Sanborn Neuhart, 9024Jones, Omaha, Nebr. Filed Mar. 1, 1963, Ser. No. 262,080 5 Claims. (Cl.237--12.4)

This invention relates to a method and apparatus for supplying auxiliaryheating steam to the heating system of railroad trains. In recent years,it has become the practice to operate longer passenger trains. It is notunusual under present standards to run trains having as many astwenty-five cars.

To meet the increased demand for steam, it has been conventionalpractice to provide additional steam generators located at the head endof the train. Except under extreme weather conditions, this expedienthas been proven to be satisfactory. However, under conditions of extremecold, it has been found that it is impossible to heat the rear cars of along passenger train adequately. The addition of still more steamgenerating equipment at the head end of the train is not an answer tothe problem, since the volume of steam generated by the equipment cannotbe distributed to the cars through the existing steam lines.

It has also been proposed to locate auxiliary steam generating equipmentin other parts of the train, either at the rear end or an intermediatelocation. This proposal has not proved satisfactory because thecondensate traps are inadequate to handle the large volume of condensatewhich accumulates at the point where the auxiliary steam flow meets thesteam flow from the head end of the train. This point of intersection ofthe two steam flows is reasonably constant in location and is the pointof maximum condensate accumulation. It will be apparent that neither ofthese proposals is an answer to the problem, since each would requirethat the existing equipment be extensively modified in order toaccommodate the increased steam flow or the increased amount ofcondensate. Neither of these solutions is economically acceptable.

According to the present invention, auxiliary heating steam, at a lowerpressure than head end steam pressure, is supplied to the train from anintermediate location or from the rear end of the train by anintermittently operable steam generator. This steam generators operationis controlled in response to the pressure existing in the steam linewhere the auxiliary generator is to be located. The auxiliary steamgenerating equipment is completely self-contained and operatesindependently of the head end steam generating equipment. The auxiliarysteam generator is normally inactive, but, when the pressure in thesteam lines falls below a first predetermined value, its operation iscommenced. Operation will continue until the pressure has risen above asecond predetermined value and thereafter maintained above said firstvalue for a predetermined time interval.

In the preferred embodiment of the invention, the auxiliary steamgenerator includes an internal combustion engine which drives anelectric generator which in turn supplies electric power to operate amotor-driven compressor and a motor-driven fuel pump which supply fueland air to the burners of the auxiliary steam generator. When thepressure at the location of the auxiliary steam generator falls to afirst predetermined value, automatic controls start the auxiliary steamgenerator.

During the time steam is being supplied to the steam line by theauxiliary steam generator, pressure in the steam line is building up andthe steam flows from the auxiliary steam generator forward toward thehead end generator. This means that the point of minimum pressure in thesteam line between the auxiliary steam generator and the head endequipment changes location.

Because this minimum pressure point is variously located, the point ofmaximum condensate accumulation is also moved and the condensate flow isdistributed to the traps on a number of cars located between steamgenerators.

In this way it is possible for the existing steam traps to accommodatethe increased condensate flow. There is no increase in the volume ofsteam being supplied by the head end equipment. this invention is notsubject to the problems which prevented the adoption of the previouslyknown proposals mentioned above.

The invention will be described herein having reference to theaccompanying drawing in which the system is shown in schematic form.

Reference numeral 11 indicates the steam line which extends through thetrain from one end to the other, the

independent sections being connected serially by flexible Each car isprovided with a condensate trap 13. Reference numeral 14 indicates theconnectors 12 between cars.

normally charged brake pipe of the conventional pneumatic brake system.This brake pipe 14 is made up of sections serially connected by means offlexible hose 15 between successive cars. Air is supplied to the brakepipe 14 through an engineers brake valve 16. The main steam generatorwhich supplies steam to the head end of the steam line 11 is indicatedat 17. This generator may consist of more than one steam generatingunit. The number of units used is selected in accordance with the aweather conditions to be encountered during the trip of As shown in thedrawing, an auxiliary steam generator 18 is provided and is arranged tosupply steam to the rear end of the steam line 11 under conditions to bedescribed. Reference numeral 19 indicates a pressure actuated meanswhich controls switches 21 and 22. The

pressure motor of this switch 19 is connected to the steam A pressureactuated motor 23 operline 11 as shown. ates switch 24. This motor 23 isconnected to the brake pipe as shown. Connected in series circuit withthe switches 21 and 24 is a switch 25 which is operated by a thermostatT sensitive to outdoor temperature. Also connected in series with theseswitches is an engine control panel generally indicated at 26 and abattery 27.

The auxiliary steam generator 18 is provided with a motor-driven fuelpump 28 and a motor-driven air compressor 29 by which fuel and air aresupplied to the burner schematically indicated at 31. Current issupplied to drive the fuel pump and the air compressor by an alternator32 which is in turn driven by diesel engine 33 when the latter is inoperation. The starter for the diesel engine is indicated at 34. Thecontrol circuit also includes timers 35 and 36. The auxiliary steamgenerators output line 37 is selectively connected to atmosphere throughvalve 38 or to the train steam line through valve 39. These valves 38and 39 are operated in response to the pressure in the steam generatorand valve ambient temperature falls below 40 F. The switch 21 will closeonly when the pressure at the rear end of the train line falls belowpsi. When all three switches are closed, a relay in the engine control26 will energize the starter 34 to start the diesel engine 33. This willcause operation of the alternator to supply current It will be seen thatthe system of to the fuel pump and to the air compressor and start theoperation of the auxiliary steam generator 18. During initial heating ofthe steam generator, the steam is vented to atmosphere through valve 38.The valve 38 will, by reason of its internal flow resistance, cause aback pressure to develop in the steam generator 18. When the steampressure reaches 50 psi, the valve 38 closes and the valve 39 opens,thus connecting the auxiliary steam generator 18 to the steam line 11.Continued operation of the auxiliary steam generator will cause steamline pressure to rise until it reaches 150 pounds at which time theswitch 22 will open. Opening of this switch causes the timer 35 to closevalve 41 and to commence timing. Unless the switch 22 recloses within apredetermined interval of time, about 12 minutes, this timer will causethe second timer 36 to commence operation. Switch 22 will reclose onlyif steam line pressure falls below 100 psi. The second timer 36 controlsa water fill valve and during its operation the auxiliary steamgenerator is refilled. After 4 /2 minutes, the timer 36 will completeits cycle and the diesel engine will be stopped and the auxiliary steamgenerator will shut down. If steam line pressure falls below 100 psi.before the timer 35 completes its cycle, it will be reset to zero andwill start to run again when steam line pressure reaches 150 p.s.i.

Typically, the head end steam generators are operated to supply steam atapproximately 250 p.s.i. This steam is used for other purposes thanheating the cars in the train, the principal secondary use being use inthe galley of the dining car in steam tables and the like. Thesesecondary steam users impose a variable loadand hence the steamavailable for heating at any given time is variable. The steam pressurein the steam line becomes progressively lower as the distance from thesteam generator becomes greater. This pressure gradient is commonlyknown as taper. The pressure of steam supplied to the train line by theauxiliary steam generator will also exhibit taper. Because the two steamgenerators are operated at different pressures, the gradients of thepressure drop from the two steam generators are different. Thisdifference in gradient contributes to the change in location of thepoint where the two steam flows meet when both the head end and theauxiliary steam generators are operating. Observation indicates that thepoint of intersection moves through a greater distance along the trainline when the auxiliary steam generator is operated at a pressure lowerthan the operating pressure of the head end steam generator. The shiftin location of the point of intersection of the two steam flows is alsoaugmented by the fact that operation of the auxiliary steam generator iscyclic. This means that the point of intersection moves forward throughthe train when the auxiliary steam generator is first put into operationand moves backward through the train when the auxiliary steam generatorshuts down. The movement of this point of intersection of the steamflows is critical to the practical operation of the heating systemof thepresent invention. Without this movement the condensate traps would betoo small to accommodate the additional condensate load imposed on themby the addition of the auxiliary steam generator. It would not befeasible for a railroad to reequip all of its passenger cars with largercondensate traps because the expense wouldbe prohibitive. According tothe present invention, it is possible to operate longer trains undersevere weather conditions and still maintain a comfortable heat in thecars, without modifying the steam distribution system in any way.

There are various secondary and manual controls on the auxiliary steamgenerator which have not been described, since they are, in the main,conventional, there seems no need to include a detailed description ofthem.

The practice of the invention is not limited to the use of th pe fic equpment shown in the d awing d 4 the scope of the present invention isintended to be measured by the appended claims.

What is claimed is:

1. In a railroad train having a steam line extending therethrough, saidsteam line having a plurality of condensate traps connected therewith,and main steam generating means connected to supply steam to said steamline the method of supplying steam from an auxiliary steam generator tothe steam line at a point remote from the main steam generating meanswhich method consists in admitting steam from the auxiliary generator tothe steam line at said remote point when the steam pressure in the lineat that point falls below a first predetermined value; and terminatingthe supply of steam from the auxiliary generator after pressure in thesteam line reaches a second predetermined value higher than the first,whereby the point of lowest pressure in the steam line is caused to moveback and forth from said remote point so that condensate is distributedto a plurality of said traps for disposal.

2. The method defined in claim 1 in which said second predeterminedvalue is less than the pressure of steam generated by the main steamgenerating means.

3. In a railroad train having a steam line extending therethrough andmain steam generating means connected to supply steam to said trainline, the method of supplying steam from a normally inactive auxiliarysteam generator to the steam line at a point remote from the main steamgenerating means which method consists of commencing operation of theauxiliary steam generator when the pressure in the line at said pointfalls below a first predetermined value; establishing fiow from saidauxiliary steam generator to the steam line when pressure in that steamgenerator reaches a predetermined level; terminating flow from saidauxiliary steam generator to the steam line when pressure in the steamline exceeds a second predetermined value higher than the first;recommencing the flow of steam from the auxiliary steam generator to thesteam line if, within a predetermined interval of time, the pressure inthe steam line falls below said first value; and shutting down saidauxiliary steam generator if the pressure in the steam line remainshigher than said first predetermined value throughout said predeterminedtime interval after the termination of flow from said auxiliary steamgenerator.

4. In a heating system for the cars of a railroad train of the type inwhich said system includes main steam generating means, a steam lineextending through said train, a plurality of condensate traps connectedwith said steam line, and means connecting said generating means tosupply steam to said line, the improvement which comprises an auxiliarysteam generator; conduit means connecting said auxiliary steam generatorwith said steam line at a point remote from the connecting means fromthe main steam generating means; and pressure-responsive valve meanscontrolling flow through said conduit means, said valve being open whensteam line pressure at said point falls below a first predeterminedvalue and being closed when steam line pressure at said point risesabove a second predetermined value higher than the first value, wherebythe point of lowest pressure in the steam line is caused to move backand forth from said remote point so that condensate is distributed to aplurality of said traps for disposal.

5. In a heating system. for cars of a railroad train of the type inwhich said system includes main steam generating means, a steam lineextending through said train, and means connecting said generating meansto said line, the improvement which comprises a normally inactiveauxiliary steam generator; conduit means connecting said auxiliary steamgenerator with said steam line at a point remote from the connectingmeans from the main steam generating means; normally closed valve meansin said conduit means; starting means for said auxiliary steam generatorresponsive to pressure in said steam lineand I effective to put saidauxiliary steam generator in operation when the pressure in the steamline at said point falls below a first predetermined value; meansresponsive to pressure in said auxiliary steam generator and operativelyconnected with said normally closed valve means to open said valve meanswhen pressure in said auxiliary steam generator rises above apredetermined level; switch means connected to be closed when pressurein said steam line at said point reaches a second predetermined valuehigher than the first; timing means rendered effective by closure ofsaid switch means; means effective to re-open said switch means ifpressure in the steam line falls below said first predetermined valuewithin a predetermined interval of time, and to reset said timer; andmeans to shut down said auxiliary steam generator if the pressure in thesteam line remains above said first predetermined value throughout saidpredetermined time interval after closure of said switch means.

References Cited by the Examiner UNITED STATES PATENTS 923,968 6/1909Gold 237 6 1,257,801 2/1918 Burke 237-61 X 2,288,021 6/1942 Ostermann237-42 X 2,356,372 8/1944 Appel 237-6 2,437,673 3/1948 Appel 23762,480,883 9/1949 Schramm 237 61X FREDERICK L. MATTESON, 111., PrimaryExaminer. EDWARD J. MICHAEL, Examiner.

1. IN A RAILROAD TRAIN HAVING A STEAM LINE EXTENDING THERETHROUGH, SAIDSTREAM LINE HAVING A PLURALITY OF CONDENSATE TRAPS CONNECTED THEREWITH,AND MAIN STEAM GENERATING MEANS CONNECTED TO SUPPLY STEAM TO SAID STEAMLINE THE METHOD OF SUPPLYING STEAM FROM AN AUXILIARY STEAM GENERATOR TOTHE STEAM LINE AT A POINT REMOTE FROM THE MAIN STEAM GENERATING MEANSWHICH METHOD CONSISTS IN ADMITTING STEAM FROM THE AUXILIARY GENERATOR TOTHE STEAM LINE AT SAID REMOTE POINT WHEN THE STEAM PRESSURE ON THE LINEAT THAT POINT FALLS BELOW A FIRST PREDETERMINED VALUE; AND TERMINATINGTHE SUPPLY OF STEAM FROM THE AUXILIARY GENERATOR AFTER PRESSURE IN THESTEAM LINE REACHES